JWSS - Journal of Water and Soil Science

Nowadays, inappropriate land use and degradation of natural resources have led to increase of flood, soil erosion etc. In such critical conditions, an integrated planning in natural resource management with the goal of control, reclamation and conservation seems to be necessary and these kinds of purposes can be reached by an integrated watershed management. Comprehensive management of watersheds is a coordinated and harmonic management of physical, biological, social and economic systems, which provides conditions that minimize the negative impact on resources while safeguarding the interests of the community. In this research, in line with the goals of resource management, the impacts and consequences of physical, economic and ecological criteria on vegetation condition changes were evaluated with focus on elimination of flood and soil erosion issues in Nahrein watershed (with the area of 18800 ha located in Tabas). The evaluation was done by considering four management activities: management of grazing, planting, seeding, and sowing. The prioritization of the scenarios was carried out using analytical hierarchy process (AHP) technique. Then, based on the suggestions and comments from relevant experts, the evaluation of available options was done by pairwise comparison matrix method. After calculations, economic criteria was selected as the most important criteria and management activity of sowing and scenario No. 16 were introduced as the most appropriate reform plan and scenario for the study area which is selected based on available criteria

The utilization of organic amendments in the reclamation of saline-sodic soils can reduce the necessity for the application of chemical Ca⁺² sources. In this research, soil leaching experiments were conducted in CRD as split factorial. The main factors were 1) amendment type including manure and compost, 2) amendment rate including 1, 3, and 5 percentage w/w, and 3) leaching stage with 5 levels including without leaching, once, twice, three times, and four times leaching, every time with one pore volume and with 30 days’ intervals. All columns were incubated for 30 days after the addition of amendments and then were leached. The parameters in each column were studied in three depths as a subplot. After 120 days, EC and ESP of soils amended with both types of conditioners reduced under 5 dS m^-1 and 15%, respectively. After 150 days, the exchangeable K and Mg were reduced by both conditioners. Exchangeable Ca increased significantly in both amendments at the end of the 5th month. The efficiency of 1% by weight of two conditioners in improving the salinity and sodicity characteristics of soils was the same as other rates. There was not a significant difference between leaching by 3 and 4 pore volume in both conditioners in the most of parameters. In leaching treatment with three pore volumes using 1 percentage w/w of manure and compost, soil EC decreased by 80% and 71% and soil ESP by 44.5% and 35%, respectively.